Furnace



Patented Deo. 25, 1894.

FURNAGE.

H. D. SMITH.

(No Model.)

OTQLITHO.. WANINGTON D C n s w us so.. PN

UNITED STATES PATENT Orr-ics.A

HENRY D. SMITH, OFv CHICAGO, ILLINOIS.

` FU RNACE.

SPECIFICATION forming part of Letters Patent No. 531,394, dated December 25, 1894.

v Application iiled April 24, 1393 Serial No.\4'71|716. (No model.)

To all whom it may concern.;

Be it known that I, HENRY D. SMITH, a citizen of the United States, residing at Chicago,

in the county of Cook and State of Illinois,

,have invented certain new and useful Imfor its object to provide a furnace in whichj the combustion will beperfect enough to 'insure the combustion of all carbon so as `to render it practically smokeless. c

To this end my invention consists in providing means whereby an abundant supply of fresh air may be introduced into the furnace, and also in providing for a better draft,

as will be hereinafter specied and as illustrated in the drawing. Y

That which I regard Vas new will` be set forth in the claims.

In the drawing,1 indicates a furnace, which is provided with a forward combustion chamber 2 and a rear combustion chamber 3 located somewhat belowthe forward' chamber 2. s

4 indicates the grate-bars of the chamber 2, which grate-bars may be of any desired pattern.

5 indicates the grate-bars of the chamber 3, which are tubular, as shown.

6 indicates an upper furnace door opening into the chamber 2.

7 indicates a lower furnace door opening into an ash-pit 8 under the grate-bars 4 of the chamber 2.' The bottom of the ash-pit 8 is about upon a level with the grate-bars 5, as shown.

9 indicates a passage leading from the ashpit 8 to the combustion chamber 3, in which passage is a door 19.

10 indicates an ash-pit located under thev .through the medium of a door 11. The airconduit 10 is cut off'from communication with the ash-pit 8 through the medium of an ilnperforate wall 19 of any material suitable for the conditions required. As here shown the imperforate wall is arranged horizontally, and itextends from the front wall of the furnace structure to the passage-way 12. vThe imperforate wall makes the air-conduit 10 a separate and distinct channel for the passage of air to the hollowy grate-bars 5. f1.2 indicates a passage way leading from the ash-pit 10 to the open ends of the gratebars 5.

13 indicates a' slide adapted to close the opening of the passage way 12, which slide is operated by a rod 14 projecting through the front of the furnace, as shownpwhich construction provides for operating the slide 13 from the front of the furnace.

15 indicates a smoke-stack into which the Vchamber 3 opens. l

16 indicatesa chamber located under the smoke-stack 15, into which chamber the gratebars 5 open.

17 indicates a grating which forms the top of the chamber 16 and serves to prevent cinders and ashes from falling into said chamber.

v18 indicates a slide or door at the side of the furnace, through which access may be had to the chamber 3.

The fire is built upon the grate-bars 4 in the chamber 2, and after arriving at a certain point in its combustion a portion of it is pushed back upon the grate-bars 5, suificient fuel being retained upon the grate-bars 4 to provide for igniting fresh fuel. Air, passing through the ash-pit 8, serves to insure goed combustion inthe chamber 2, and perfect combustion of the fuel in the rear chamber is secured by the admission of fresh air thereto through the ash-pit 10. By this construction the air which is fed to the rear chamber 3 is fresh and not vitiated by a prior passage over burning fuel. To further provide for proper combustion the furnace is fed by a current of hot fresh airwhich passes from the separate air-conduit 10iL through the passage 12 and grate-bars 5 to the chamber 16, and thence through the grating 17 to the smoke-stack, and any particles remaining unconsumed will IOO be caused to ignite owing to the intense heat thereby created.

lf it is desired to shut o the supply of hot air it may be accomplished by moving the slide 13,closing the opening of the passage 12.

I am aware that furnaces having front and rear combustion chambers located upon dif ferent levels are not new; but in all such furnaces with which I am familiar the rear combustion chamber has been fed through the same air passage as the front chamber, there being no provision for separating the two air passages. Such constructions are inefficient in that the supply of air conducted to the rear furnace is robbed of its oxygen, and has little effect upon the fire.

That which I claim as my invention, and desire to secure by Letters Patent, is

1. The combination with a furnace structure having a smoke conduit 15 at the rear, of an air chamber 16 located under the smoke conduit, two combustion chambers 2 and 3 arranged one in rear of the other, a passage 9 leading from the ash pit of the front combustion chamber to the rear combustion chamber, hollow air-conducting grate-bars 5 for the rear combustion chamber, connected with the air chamber under the smoke conduit, a passage-way 12 leading from the ashpit of the rear combustion chamber to the front open ends of the hollow grate bars, an air conduit for supplying fresh air to the front combustion chamber, and a separate air conduit for supplying air to the rear combustion chamber, substantially as described.

2. The combination with a furnace structure having a smoke conduit 15 at the rear, of an air chamber 16 located under the smoke conduit, two combustion chambers 2 and 3 arranged one in rear of the other, hollow air conducting grate bars 5 for the rear combustion chamber, connected with the air chamber under the smoke conduit, a passage-way 12 leading from the ash-pit of the rear combustion chamber to the front open ends of the hollow grate-bars, a slide or damper 13 for closing communication between the said passage-Way and the ash-pit of the rear combustion chamber, an air conduit for supplying fresh air to the front combustion chamber, and a separate air conduit for supplying fresh air to the rear combustion chamber, substantially as described.

8. The combination with a furnace structure having a smoke-conduit atthe rear, two communicating combustion chambers 2 and 3 arranged one in rear of the other, and hollow air conducting grate-bars 5 for the rear combustion chamber having communication with the smoke-conduit, of a separate air-conduit 10 closed against communication with the front ash-pit; and supplying fresh air to the forward ends of the hollow grate-bars, substantially as and for the purposes described.

4. The combination with a furnace structure having a smoke conduit l5 at the rear, of an air chamber 16 located under the smoke conduit, two combustion chambers 2 and 3 arranged one in rear of the other, front grate bars 4, a passage 9 leading from the ash-pit of the front combustion chamber to the rear combustion chamber, hollow air conducting grate bars 5 for the rear combustion chamber, connected with the one chamber under the smoke conduit, a passage-way 12 leading,r from the ash-pit of the rear combustion chamber to the front open ends of the hollow grate bars, a slide or damper 13 for closing communication between the said passage-way and the rear ash-pit, an air conduit for supplying fresh air to the front combustion chamber, and aseparate airconduit for supplying fresh air to the ash-pit of the rearcombnstion chamber, substantially as described.

HENRY D. SMITH.

Witnesses:

JOHN L. JACKSON, RALPH VAN DYKE. 

